Xiaomi Mix Fold 4

Xiaomi MIX Fold 4 is an Android-based foldable smartphone manufactured by Xiaomi. It was released in 2024 and sold exclusively in China.
When released, it was one of the thinnest commercially available book-style foldable phones, at 9.47mm when closed and 4.6mm when opened. According to Xiaomi, the thinness was achieved with an "all-carbon architecture", including a hinge made with carbon fiber.
It has four cameras. It supports both wired and wireless charging.

Reception

Reception of the Mix Fold 4 was negatively impacted by problems with software and user experience. Tom's Guide called the phone solid and praised its display and battery life but said its camera was disappointing. According to a 2025 report, Xiaomi was planning to release a new model in 2026 that would address some of the flaws of the Mix Fold 4.
A review in the South China Morning Post praised the model's thinness, sleekness, and lightness. It also spoke positively about the display, performance, and cameras, but stated that these features were not innovations compared to existing foldable phones.